LONDON — Before boarding the plane that took the Spanish league trophy back home to Barcelona, Gerard Piqué spoke in Granada, Spain, of the team’s biggest opponent this season — itself.

“We had to win it twice,” Piqué told reporters. “When we were 8 or 10 points ahead, we believed we had it won. Then there was a moment when it seemed we lost it, although we always depended only on ourselves.”

Spain’s La Liga was the last of the big leagues to be decided this season. Bayern Munich, Juventus and Paris St.-Germain turned Germany, Italy and France into one-horse races (the same horses as last year), while Leicester City surprised everybody by winning, easily in the end, in England.

Spain went the full distance, with all three front-runners — Barcelona, Real Madrid and Atlético Madrid — winning their final games on Saturday. The race finished in that order, with Barça, Real and Atlético separated by just three points.

All the rumors of top teams offering incentives — not bribes to throw games, but incentives to players on other clubs to play hard against the other teams chasing the title — came to nothing.

You could offer Granada the world, but it had neither the skills, the stamina nor the belief to do anything other than succumb, 3-0, in its own stadium against Barcelona.

You could likewise offer any amount of encouragement to Deportivo La Coruña, and its fight, too, would be feeble against Real Madrid. Their match was effectively over before halftime after Real’s Cristiano Ronaldo scored twice and hit the woodwork twice before he was taken off to rest.

The reality is that Barcelona and Real are superior clubs in their own league, while Atlético is the exception to the supposed rule that no other force can challenge them.

Indeed, their powers extend to Europe, where Barcelona won the Champions League last year and where the two Madrid giants will lock horns in the final in Milan on May 28.

Players always say that the Champions League is the glory, while the domestic leagues offer the greater test of their skills, consistency and staying power.

Yet superstars dominate this league marathon. Ronaldo’s two goals on Saturday — one poached from a few yards, the other deflected into the net off a defender’s back — gave him 35 goals in the 38-game league season and an unprecedented sixth consecutive season of notching 50 or more goals over all.

Barcelona has a man who beat Ronaldo this particular season. And this time, it is not Lionel Messi.

With three goals against Granada, Luis Suárez took his tally to 14 goals over the last five games, 40 in La Liga for the season and 59 in all competitions.

Barcelona has one more game to play, the Copa del Rey final against Sevilla on Sunday.

Messi, Neymar and Suárez combined for 90 of the 112 goals that Barcelona scored this season as it retained its league title. And while Messi has coped with injuries and changed his role toward being a midfield playmaker, Neymar also emphasized Saturday that he is perfectly content to feed the predator that Suárez has hungrily become.

Where it went wrong, or almost went wrong, for Barcelona was back in April, when that attacking trio flew halfway across the world to play energy-sapping World Cup qualifying games, Messi for Argentina, Neymar for Brazil and Suárez for Uruguay.

Real Madrid caught them while they were still jet-lagged. Losses to Real Sociedad in La Liga and to Atlético Madrid in the Champions League came thick and fast, and suddenly Barcelona looked weary and vulnerable, almost a spent force.

Barça’s coach of few words, Luis Enrique, said then that his players had five games to save their season and that they thrived on such pressure. He repeated the same thought to the team over the weekend.

Barcelona’s response? Five games, five wins, 24 goals scored and none conceded. In Granada, the field was supposed to be the great leveler, but the home club did not muster a shot on goal until deep into the second half.

The grass had been left long, deliberately, to prevent smooth running with the ball and the slick interchange of Barcelona’s passing. That, and massed clusters of defenders, kept Barcelona scoreless for 22 minutes.

Then came a movement involving eight players and 16 passes over the long grass, followed by one sharp finish by Suárez. He possesses the art of timing, almost hiding himself until he smells the opportunity to pounce.

He did so again before halftime, on the end of a much more economical buildup. Javier Mascherano advanced over the halfway line, lofting a long, high, angled pass, and Dani Alves, nominally a fullback, sped forward and hooked the ball toward the near post, where Suárez exploited the space between the goalkeeper and the last defender.

The long way, the short way, any way is good for Suárez in this mood. He completed his third hat trick in five games off a pass from Neymar.

Barcelona is the Spanish champion for the sixth time in eight years. Andrés Iniesta and Messi have been involved in eight La Liga titles to date.

Their club was banned from making transfers over two seasons because it broke FIFA’s youth recruitment rules. This left the club short of senior players, and the latest triumph has largely been achieved by fielding the same players in all competitions.

“Twenty years ago,” concluded Piqué, “we might not have won this title because Barça used to be sunk by its own pessimism. This generation has changed that — it faces up, you can trust in it.”

The public celebration was scheduled for Sunday in the Catalan capital.